The interplay of essentialism and modal logic is a major topic in the logic and metaphysics of modality. Quine 1953 argued that quantified modal logic (QML) entails essentialism, the view that an object can have a property essentially, independently of how it is referred to. Since he found essentialism to be unintelligible, Quine concluded by modus tollens that QML should be rejected. Kripke 1963 and Marcus 1967 have contributed to the rehabilitation of QML by showing how it can be made sense of within a suitable semantic framework. Others, such as Parsons 1969 and McKay 1975, have argued that QML is not committed to the thesis of essentialism in the way Quine thought. Now that the intelligibility of QML is no longer at issue, a central problem in the contemporary debate is whether the notion of essence can be understood in modal terms. A classical modalist analysis of essence is due to Moore 1919: x is essentially P iff x is necessarily P (or, in conditional form: iff x is necessarily P, if existent). This reduction of essence to pure QML has been found wanting by Fine 1994. As a consequence, the Moorean definition has been mostly abandoned (but see Cowling 2013). Some proposals have emerged that attempt to understand essence by means of revisions or extensions of standard QML. Zalta 2006 and Wildman 2013 have proposed to reduce essence to a combination of modal and non-modal notions. Correia 2007 has put forward an analysis of essence carried out in a modal logic which is more fine-grained that standard QML. Fine 1995, 2000 has formulated a quantified intensional logic for the notion of essence.

This is Part I of a two-part essay introducing case-intensional first-order logic (CIFOL), an easy-to-use, uniform, powerful, and useful combination of first order logic with modal logic resulting from philosophical and technical modifications of Bressan’s General interpreted modal calculus (Yale University Press 1972). CIFOL starts with a set of cases; each expression has an extension in each case and an intension, which is the function from the cases to the respective case-relative extensions. Predication is intensional; identity is extensional. Definite descriptions (...) are context-independent terms, and lambda-predicates and -operators can be introduced without constraints. These logical resources allow one to define, within CIFOL, important properties of properties, viz., extensionality (whether the property applies, depends only on an extension in one case) and absoluteness, Bressan’s chief innovation that allows tracing an individual across cases without recourse to any notion of “rigid designation” or “trans-world identity.” Thereby CIFOL abstains from incorporating any metaphysical principles into the quantificational machinery, unlike extant frameworks of quantified modal logic. We claim that this neutrality makes CIFOL a useful tool for discussing both metaphysical and scientific arguments involving modality and quantification, and we illustrate by discussing in diagrammatic detail a number of such arguments involving the extensional identification of individuals via absolute (substance) properties, essential properties, de re vs. de dicto, and the results of possible tests. (shrink)

Let us call a property that is essentially dispositional a potency.1 David Armstrong thinks that potencies do not exist. All sparse properties are essentially categorical, where sparse properties are the explanatory properties of the type science seeks to discover. An alternative view, but not the only one, is that all sparse properties are potencies or supervene upon them. In this paper I shall consider the differences between these views, in particular the objections Armstrong raises against potencies.

The author puts forth an approach to propositional attitude contexts based upon the view that one does not have beliefs of ordinary extensional entitiessimpliciter. Rather, one has beliefs of such entities as presented in various manners. Roughly, these are treated as beliefs of ordered pairs — the first member of which is the ordinary extensional entity and the second member of which is a predicate that it satisfies. Such an approach has no difficulties with problems involving identity, such as of (...) The Morning Star and The Evening Star (section 1). Given the second members of the pairs, the modes of presentation, it is quite natural to allow exportation everywhere. There is no need for essentialism. (One also can have non-essentialistic modal logic if one grants analyticity or the like.) (section 2). Given that the second member of the pair need only be one that is satisfied by the entity that is the first member (and need not be specificative), the method has no difficulties when one is concerned only with discriminations (and not specifications) (section 3). When this method is combined with the Frege-Carnap method of descriptions, fictional entities can be accommodated; Goodman''s unicorn-picture and the like can be brought within a Tarskian semantics; and Geach''s difficulties with intentional identity appear to be handled (section 4). Given the author''s ordered pair construals, there appears to be no additional need for notional construals; i.e., the author''s one unified method appears satisfactory for dealing with both traditionalde re (relational) andde dicto (notional) construals. The Paradox of the Knower and the like do not appear formulatable against the author''s approach. (section 5). The author also argues against the basic principles behind the Church-Langford translation argument (section 6). (shrink)

In Fine 1994, Kit Fine challenges the view that the notion of essence is to be understood in terms of the metaphysical modalities, and he argues that it is not essence which reduces to metaphysical modality, but rather metaphysical modality which reduces to essence. In this paper I put forward a modal account of essence and argue that it is immune from Fine’s objections. The account presupposes a non‐standard, independently motivated conception of the metaphysical modalities which I dub Priorean. Arthur (...) Prior never endorsed that very conception, but in some respects his own views on the topic are so close to it, and different from all currently accepted views, that the label ‘Priorean’ is perfectly appropriate. (shrink)

This paper provides a possible worlds semantics for the system of the author's previous paper 'The Logic of Essence'. The basic idea behind the semantics is that a statement should be taken to be true in virtue of the nature of certain objects just in case it is true in any possible world compatible with the nature of those objects. It is shown that a slight variant of the original system is sound and complete under the proposed semantics.

It is my aim in this paper to show that the contemporary assimilation of essence to modality is fundamentally misguided and that, as a consequence, the corresponding conception of metaphysics should be given up. It is not my view that the modal account fails to capture anything which might reasonably be called a concept of essence. My point, rather, is that the notion of essence which is of central importance to the metaphysics of identity is not to be understood in (...) modal terms or even to be regarded as extensionally equivalent to a modal notion. The one notion is, if I am right, a highly refined version of the other; it is like a sieve which performs a similar function but with a much finer mesh. (shrink)

This landmark work provides a systematic introduction to systems of modal logic and stands as the first presentation of what have become central ideas in philosophy of language and metaphysics, from the "new theory of reference" and non-linguistic necessity and essentialism to "Kripke semantics.".

An appraisal of the current status of the modalities and of quine's arguments against them. The author accepts "quine's thesis," that one cannot quantify into referentially opaque contexts, And argues that nobody has succeeded in making sense of such quantification. However, It is shown that modal constructions, Being constructions on general terms and sentences, Can be referentially transparent and extensionally opaque and that consequently the collapse of modal distinctions warned against by quine in "word and object" can be avoided. This (...) combination of referential transparency and extensional opacity is just what quine means by essentialism, And the author therefore agrees with quine that quantified modal logic commits one to essentialism. (shrink)

The purpose of the present paper is to provide a way of understanding systems of logic of essence by introducing a new semantic framework for them. Three central results are achieved: first, the now standard Fitting semantics for the propositional logic of evidence is adapted in order to provide a new, simplified semantics for the propositional logic of essence; secondly, we show how it is possible to construe the concept of necessary truth explicitly by using the concept of essential truth; (...) finally, Fitting semantics is adapted in order to present a simplified semantics for the quantified logic of essence. (shrink)

Recent work on the philosophy of modality has tended to pass over questions about iterated modalities in favour of constructing ambitious metaphysical theories of possibility and necessity, despite the central importance of iterated modalities to modal logic. Yet there are numerous unresolved but fundamental issues involving iterated modalities: Chandler and Salmon have provided forceful arguments against the widespread assumption that all necessary truths are necessarily necessary, for example. The current paper examines a range of ways in which one might seek (...) to identify limited regions within which some of the most well-known principles featuring iterated modalities may safely be assumed. (shrink)

It has been argued by Bernard Linsky and Edward Zalta, and independently by Timothy Williamson, that the best quantified modal logic is one that validates both the Barcan Formula and its converse. This requires that domains be fixed across all possible worlds. All objects exist necessarily; some – those we would usually consider contingent – are concrete at some worlds and non-concrete (but still existent) at others. Linsky and Zalta refer to such objects as ‘contingently non-concrete’. I defend the standard (...) usage of the word ‘exists’, and the view that many objects exist only contingently. I argue that the Linsky/Zalta analysis, and to a lesser extent Williamson’s, suffers not only from a peculiar ontology but also from two related formal difficulties. Their analysis gives either counter-intuitive or ad hoc results about essences, and it fails to accommodate contingently existing abstracta. (shrink)

The central thesis of this dissertation is that the recently proposed Causal Theories of Reference by K. Donnellan, H. Putnam, and especially S. Kripke provide support for Scientific Realism as developed in the theories of J. J. C. Smart, H. Putnam, and especially R. Boyd, on the face of the most serious challenge to scientific objectivity contained in the writings of the Relativists S. Toulmin, N. R. Hanson, T. S. Kuhn, and P. Feyerabend. I have argued accordingly that all the (...) relativistic arguments are either weak or are reducible to a strong formal argument about the reference of scientific terms and the categoricity of scientific systems. This argument is shown to be even stronger because of the important role that reference plays in the objectivity of science. I proceed to show then that the employment of this argument by the Relativists rests on the Traditional Theory of Reference. In the final part, I argue that the Traditional Theory of Reference has become untenable, both on account of internal difficulties and because of advances in Modal Logic that show some of its basic tenets to be erroneous. In its place a new theory has been proposed by Kripke, the Causal Theory of Reference when avoids the internal difficulties of the Traditional Theory and is sensitive to modal distinctions. My conclusion is that the new theory of reference offers not only negative support to Scientific Realism, by undercutting the argument of its most serious challenger, but provides postitve support as well by way of foundation and clarification of its major tenets. As a result a new conception of science is beginning to emerge, in which the notions of necessity, cause and essential property play a key role. (shrink)

We say that things happen accidentally when they do indeed happen, but only by chance. In the opposite situation, an essential happening is inescapable, its inevitability being the sine qua non for its very occurrence. This paper will investigate modal logics on a language tailored to talk about essential and accidental statements. Completeness of some among the weakest and the strongest such systems is attained. The weak expressibility of the classical propositional language enriched with the non-normal modal operators of essence (...) and accident is highlighted and illustrated, both with respect to the definability of the more usual modal operators as well as with respect to the characterizability of classes of frames. Several interesting problems and directions are left open for exploration. (shrink)

Based on her earlier ground-breaking axiomatization of quantified modal logic, the papers collected here by the distinguished philosopher Ruth Barcan Marcus cover much ground in the development of her thought, spanning from 1961 to 1990. The first essay here introduces themes initially viewed as iconoclastic, such as the necessity of identity, the directly referential role of proper names as "tags", the Barcan Formula about the interplay of possibility and existence, and alternative interpretations of quantification. Marcus also addresses the putative puzzles (...) about substitutivity and about essentialism. The collection also includes influential essays on moral conflict, on belief and rationality, and on some historical figures. Many of her views have been incorporated into current theories, while others remain part of a continuing debate. (shrink)

Modality, morality and belief are among the most controversial topics in philosophy today, and few philosophers have shaped these debates as deeply as Ruth Barcan Marcus. Inspired by her work, a distinguished group of philosophers explore these issues, refine and sharpen arguments and develop new positions on such topics as possible worlds, moral dilemmas, essentialism, and the explanation of actions by beliefs. This 'state of the art' collection honours one of the most rigorous and iconoclastic of philosophical pioneers.

This paper mentions several different sorts of "essentialism," and examines various senses in which quantified modal logic is "committed to" the most troublesome kind of essentialism. It is argued that essentialism is neither provable, Nor entailed by any contingently true non-Modal sentence. But quantified modal logic is committed to the meaningfulness of essentialism. This sort of commitment may be made innocuous by requiring that essentialism simply be made logically false; some of the consequences of taking this line are explored.

Essentialists claim that we can distinguish between an object's essential and its accidental properties. Following important developments in modal logic during the 1960s and 70s, the orthodox view was that the essential properties of an object are its necessary properties. In his influential 1994 paper "Essence and Modality", Kit Fine argues that the orthodox view is wrong. His two main claims are that first, essentiality cannot be defined in terms of necessity and second, that necessity should instead be defined in (...) terms of essentiality. In my dissertation, I aim to undermine both of his claims in order to defend a variation of the orthodox view. To do this, I first develop Fine's proposal for an essentialist definition of necessity into a more general essentialist theory of modality. I then raise a series of problems for the resulting theory. Finally, I introduce and defend a novel definition of essentiality in terms of metaphysical necessity and a notion of metaphysical dependence. (shrink)

Aristotle founds his modal syllogistic, like his plain syllogistic, on a small set of ?perfect? or obviously valid sylligisms. The rest he reduces to those, usually by means of modal conversion principles. These principles are open to more than one reading, however, and they are in fact invalid on one traditional reading (de re), valid on the other (de dicto). It is argued here that this way of framing the contrast is not Aristotelian, and that an interpretation involving modal copulae (...) allows us to see how these principles, and the modal system as a whole, are to be understood in light of close and precise connections to Aristotle's essentialist metaphysics. (shrink)

This book, one of the first full-length studies of the modalities to emerge from the debate to which Saul Kripke, David Lewis, Ruth Marcus, and others are contributing, is an exploration and defense of the notion of modality de re, the idea that objects have both essential and accidental properties. Plantinga develops his argument by means of the notion of possible worlds and ranges over such key problems as the nature of essence, transworld identity, negative existential propositions, and the existence (...) of unactual objects in other possible worlds. He also applies his logical theories to the elucidation of two problems in the philosophy of religion: the problem of evil and the ontological argument. (shrink)

Modern logicians have sought to unlock the modal secrets of Aristotle's Syllogistic by assuming a version of essentialism and treating it as a primitive within the semantics. These attempts ultimately distort Aristotle's ontology. None of these approaches make full use of tests found throughout Aristotle's corpus and ancient Greek philosophy. I base a system on Aristotle's tests for things that can never combine (polarity) and things that can never separate (inseparability). The resulting system not only reproduces Aristotle's recorded results for (...) the apodictic syllogistic in the Prior Analytics but it also generates rather than assumes Aristotle's distinctions among 'necessary', 'essential' and 'accidental'. By developing a system around tests that are in Aristotle and basic to ancient Greek philosophy, the system is linked to a history of practices, providing a platform for future work on the origins of logic. (shrink)

Pace Necessitism – roughly, the view that existence is not contingent – essential properties provide necessary conditions for the existence of objects. Sufficiency properties, by contrast, provide sufficient conditions, and individual essences provide necessary and sufficient conditions. This paper explains how these kinds of properties can be used to illuminate the ontological status of merely possible objects and to construct a respectable possibilist ontology. The paper also reviews two points of interaction between essentialism and modal logic. First, we will briefly (...) see the challenge that arises against S4 from flexible essential properties; as well as the moves available to block it. After this, the emphasis is put on the Barcan Formula (BF), and on why it is problematic for essentialists. As we will see, Necessitism can accommodate both (BF) and essential properties. What necessitists cannot do at the same time is to continue to understanding essential properties as providing necessary conditions for the existence of individuals; against what might be for some a truism. (shrink)

Due to the influence of Nathan Salmon’s views, endorsement of the “flexibility of origins” thesis is often thought to carry a commitment to the denial of S4. This paper rejects the existence of this commitment and examines how Peacocke’s theory of the modal may accommodate flexibility of origins without denying S4. One of the essential features of Peacocke’s account is the identification of the Principles of Possibility, which include the Modal Extension Principle (MEP), and a set of Constitutive Principles. Regarding (...) their modal status, Peacocke argues for the necessity of MEP, but leaves open the possibility that some of the Constitutive Principles be only contingently true. Here, I show that the contingency of the Constitutive Principles is inconsistent with the recursivity of MEP, and this makes the account validate S4. It is also shown that, compatibly with the necessity of the Constitutive Principles, the account can still accommodate intuitions about flexibility of origins. However, the account we end up with once those intuitions are consistently accommodated may not be satisfactory, and this opens up the debate about whether or not artefacts allow for some variation in their origins. (shrink)

It has been argued that a combination of game-theoretic semantics and independence-friendly (IF) languages can provide a novel approach to the conceptual foundations of mathematics and the sciences. I introduce and motivate an IF first-order modal language endowed with a game-theoretic semantics of perfect information. The resulting interpretive independence-friendly logic (IIF) allows to formulate some basic model-theoretic notions that are inexpressible in the ordinary quantified modal logic. Moreover, I argue that some key concepts of Kripke’s new theory of reference are (...) adequately modeled within IIF. Finally, I compare the logic IIF to David Lewis' counterpart theory, drawing some morals concerning the interrelation between metaphysical and semantic issues in possible-world semantics. (shrink)

Rather infamously, Kit Fine provided a series of counter-examples which purport to show that attempts to understand essence in terms of metaphysical necessity are ‘fundamentally misguided’. Here, my aim is to put forward a new version of modalism that is, I argue, immune to Fine's counter-examples. The core of this new modalist account is a sparseness restriction, such that an object's essential properties are those sparse properties it has in every world in which it exists. After first motivating this sparseness (...) restriction, I proceed to show how the resulting sparse modalism circumvents Fine's original counter-examples. After dismissing a potential problem concerning the membership relation, I conclude that, as at least one form of modalism is viable, the project of understanding essence in terms of metaphysical necessity is not so fundamentally misguided after all. (shrink)

Could one give expression to a doctrine of essentialism without running afoul of semantical problems that are alleged to beggar systems of quantified modal logic? An affirmative answer is, I believe, called for at least in the case of individual essentialism. Individual essentialism is an ontological thesis concerning a kind of necessary connection between objects and their (essential) properties. It is not or anyhow not primarily a semantic thesis, a thesis about meanings, for example. And thus we are implicitly counselled (...) not to seek for the logical reconstruction of such necessities in theories in which necessity is a de ditto matter. A more natural-seeming target is an understanding of the structure of idioms of de re necessity. Of course, de re necessities may turn out to be special cases of necessities de ditto, with what consequences it is interesting to speculate upon, but it would be preferable if the theory of individual essences were to be prosecuted initially at least without prejudice to this other matter. A theory of individual essences therefore may find it a convenience to recognize a special category of open sentence by means of which to represent de re attributions of necessity. (shrink)

The standard Kripkean semantic theories for quantified modal logic allow the individuals that exist at other worlds to vary from those that exist at the actual world. This causes a problem for those who deny the existence of non-actual individuals. I focus on two prominent strategies for solving this problem, due respectively to Bernard Linsky and Edward Zalta (who identify the possible individuals with the actual individuals) and Alvin Plantinga (who identifies the possible individuals with the individual essences). I argue, (...) contra various commentators, that both of these solutions are acceptable by the lights of those who deny the existence of mere possibilia. (shrink)

This paper will provide support for relationalism; the claim that the identity of objects is constituted by the totality of their relations to other things in the world. I will consider how Kit Fine’s criticisms of essentialism within modal logic not only highlight the inability of modal logic to account for essential properties but also arouse suspicion surrounding the possibility of nonrelational properties. I will claim that Fine’s criticisms, together with concerns surrounding Hempel’s paradox, show that it is not possible (...) to provide a satisfactory account of certain properties in abstraction from their place within a wider context. Next, we will shift attention to natural kinds and consider the notion that relevance plays in metaphysical accounts of identity, by examining Peter Geach’s notion of relative identity. I will argue that the intensional relation between subject and object must be included in a satisfactory account of metaphysical identity. (shrink)

Some recently-proposed counterexamples to the traditional definition of essential property do not require a separate logic of essence. Instead, the examples can be analysed in terms of the logic and theory of abstract objects. This theory distinguishes between abstract and ordinary objects, and provides a general analysis of the essential properties of both kinds of object. The claim ‘x has F necessarily’ becomes ambiguous in the case of abstract objects, and in the case of ordinary objects there are various ways (...) to make the definition of ‘F is essential to x’ more fine-grained. Consequently, the traditional definition of essential property for abstract objects in terms of modal notions is not correct, and for ordinary objects the relationship between essential properties and modality, once properly understood, addresses the counterexample. (shrink)